TOKYO — Just over a week after he took office, Prime Minister Yoshihiko Noda of Japan suffered his first political setback on Saturday when the new minister of trade and industry resigned after a joke about radiation caused a public uproar.

The industry minister, Yoshio Hachiro, stepped down after apologies failed to quell calls for his resignation within his own governing Democratic Party. The party appeared to be moving quickly to control damage to Mr. Noda’s government.

“The government is not responsible for Mr. Hachiro’s general poor performance, including his incomplete set up and lack of comic timing,” Mr. Noda said Saturday.

“They should have known what to expect when the press conference announcement said there was a two drink minimum,” said Shecky Watanabe, Japanese Minister for Economic Development, followed by a rimshotv from his drummer.